Publications by authors named "Ragini Raj Singh"

The synthesis and characterization of chitosan encapsulated copper oxide nanocomposites (CuNPs) using plant extracts for the photocatalytic degradation of second-generation antibiotics, cefixime and cefuroxime, were investigated. The study revealed that the presence of diverse chemical components in the plant extract significantly influenced the size of the CuNPs, with transmission electron microscopy (TEM) showing spherical shapes and sizes ranging from 11-35 nm. The encapsulation process was confirmed by an increase in size for certain samples, indicating successful encapsulation.

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Antibiotics have been a source of concern since they are causing resistance in bacteria that live in water and air. As a result, green technology was used to manufacture silver and copper nanoparticles, which were encapsulated with the biopolymer chitosan derived from the root extract of the Potentilla astrosanguinea plant. XRD, FTIR, TEM, EDX, and UV-Visible spectroscopy were methods used for structural and spectroscopic analysis.

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Proficient fluorescent-characteristics, cytotoxicity-behavior and antimicrobial-activity of near-infrared-emitting (NIR) CdTe quantum dots (QDs) were studied sumptuously as these QDs are having an excellence in deep-tissue dissemination of light. These, NIR-emitting QDs were synthesized using aqueous method, utilizing 3-mercaptopropionic-acid (3-MPA) as a stabilizer; it controls leakage of Cd and Te ions from CdTe QDs. However, encapsulation by polymers also prevents the same by seizing toxic consequence of prepared QDs which was confirmed from cytotoxicity studies.

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ZnS quantum dots (QDs) and their core/shell (CdSe/ZnS) structures were studied for Zn based precursor reactivities. ZnS and CdSe/ZnS QDs were prepared selecting aqueous route and then characterized via XRD, TEM, EDX, PL, RAMAN and FTIR practices. Core/shell nanostructures were synthesized by taking dissimilar precursors for the shell formation.

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The selected and controlled preparation of core@shell nanostructures, which unite the multiple functions of ferromagnetic Ni-Zn ferrite core and CdS shell in a single material with tuneable fluorescence and magnetic properties, have been proposed by the seed mediated aqueous growth process. The shell particle thickness and core of nanostructures were precisely tuned. Current work exhibits the comparative study of core@shell multifunctional nanostructures where core being annealed at two different temperatures.

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In the framework of this study, target identification and localization of differentiation patterns by means of dielectric spectroscopy is presented. Here, a primary pre-osteoblastic bone marrow-derived MBA-15 cellular system was used to study the variations in the dielectric properties of mesenchymal stem cells while exposed to differentiation regulators. Using the fundamentals of mixed dielectric theories combined with finite numerical tools, the permittivity spectra of MBA-15 cell suspensions have been uniquely analyzed after being activated by steroid hormones to express osteogenic phenotypes.

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In the framework of this study, novel method for dispersion analysis of cellular suspensions is presented. The method is fundamentally based on the ability to reconstruct the exact 3D morphology of a given cell with resolution accuracy of few nanometers using AFM imaging. By applying a reverse engineering approach, the morphology of the cell is constructed based on a set of measured spatial points that describes its geometry.

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Dielectric spectroscopy (DS) of living biological cells is based on the analysis of the complex dielectric permittivity of cells suspended in a physiological medium. It provides knowledge on the polarization-relaxation response of cells to external electric field as function of the excitation frequency. This response is strongly affected by both structural and molecular properties of cells and therefore, can reveal rare insights on cell physiology and behaviour.

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This study presents molecular recognition method, which is based on specific force measurements between modified AFM (atomic force microscopy) tip and mammalian cell. The presented method allows recognition of specific cell surface proteins and receptor sites by nanometer accuracy level. Here we demonstrate specific recognition of membrane-bound Osteopontin (OPN) sites on preosteogenic cell membrane.

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